Volume 12, Number 2 April2002 ISSN 0268-0130 THE HERPETOLOGICAL JOURNAL Published by the Indexed in BRITISH HERPETOLOGICAL SOCIETY Current Contents HERPETOLOGJCAL JOURNAL, Vol. 12, pp. 55-6 1 (2002) A NEW ATHERIS SPECIES (SERPENTES: VIPERIDAE), FROM TAI NATIONAL PARK, IVORY COAST R . ERNST AND M.-0. RODEL Th eodor Boveri Institute Biocenter of the University, Department of Animal Ecology and Trop ical Biology (Zoology /II) . Am Hub/and, D-97074 Wiirzburg, Germany We describe a new species of the genus Atheris fromTa'i National Park, a large rainforest area in south-western Ivory Coast. Atheris sp. nov. shows close affinities to A. squamigera, but is distinguished from it by a combination of scale characteristics, as well as morphometric diffe rences in head proportions. Key words: Serpentes, Yiperidae, Atlzeris sp. nov., Ta'i National Park, Ivory Coast; INTRODUCTION The geographical co-ordinates were obtained from The genus Atheris has undergone several taxonomic Geographic Names Processing System - Phase IV, and a revisions (Broadley, 1996, 1998). However, due to the portable GPS (Garmin 12XL). The map was drawn with huge variability within the genus (Jacobi, 2001 ), the the mapping program Versamap version 2.07. taxonomic status of several taxa still remains to be set­ In order to ensure comparability, we investigated the tled. Very recently two new species of A theris have been same characters used in recent treatments of the genus described: A. acuminata from Uganda (Broadley, 1998) (Broadley, 1998; Lawson & Ustach, 2000): and A. broadleyi from Cameroon (Lawson, 1999). The suprarostrals (SRO), internasals (INS), interorbitals resurrection of A. subocularis from the synonymy of A. (IOS), maximum transverse head scales (MTHS), squamigera has currently been published (Lawson, circumorbital scales (COS), interoculabials (IOL), Noonan & Ustach, 2001). The latter species is espe­ interocunasals (ION), supralabials (SL), infralabials cially renowned forits variability (Spawls & Branch, (IL), pairs of sublinguals (PSL), dorsal scale rows at 1995). However, previous papers may have inadvert­ mid-body (MSR), ventrals and subcaudals. For discus­ ently increased its known variation in many characters sion of the diagnostic significance of these characters, by combining distinct species (Lawson, 1999). see Broadley (1998). In addition we investigated According to Hughes (pers. comm.), without a thor­ morphometric proportions of the head, as well as struc­ ough re-examination of existing museum specimens, it ture and shape of scales. Scale terminology is according cannot be decided whether A. squamigera is a geo­ to Broadley ( 1998). graphically variable species or a species complex. Head width (HW) was always taken as the maximum However, there is good evidence of more than one spe­ head width possible. Head length (HL) was measured cies being involved. Atheris hirsuta sp. nov. from Ta'i from snout to the quadratum. Interorbital distance (IOD) National Park (TNP), Ivory Coast, is one of these spe­ was measured between the circumorbital scale rows. cies that shows close affinities to A. squamigera, but Snout-eye distance (SED) was measured from the ante­ differs sufficiently to be recognized at the species level. rior comer of the eye to the snout tip. Scale and head measures were taken to the nearest 0.1 mm using a dial MATERIAL AND METHODS calliper. When scale counts differed between the sides of the head, we gave both values. Snout-vent length For comparison, we investigated museum specimens (SVL) was taken to the nearest mm using a metre rule. of A. squamigera fromthe entire Central and West Afri­ Results are summarized in Tables 1, 2 and 3. Scale can range of the species (Fig. 1). Museum specimens microstructure was examined by means of a scanning under investigation originated from, and are deposited electron microscope (SEM). in, the following collections: Staatliches Museum fur Naturkunde Stuttgart (SMNS), Zoologisches SPECIES ACCOUNT Forschungsinstitut und Museum Alexander Koenig ATHERIS HJRSUTA SP. NOV. Bonn (ZFMK), Zoologisches Museum der Humboldt Universitiitzu Berlin (ZMB), Zoologisches Institut und Holotype. SMNS 11333, male, about 6 km West of Zoologisches Museum der Universitiit Hamburg the "Station de Recherche en Ecologie Tropicale" (ZMH), Zoological Museum, University of Copenhagen (SRET 5°50'N 7°19'W), Ta'iNational Park, Ivory Coast, (ZMUC), and Zoologische Staatssammlung Mtinchen 20 September 2000, 07.00 hrs, R. Ernst leg. (ZSM). Diagnosis. Slender tree viper with rather short head, IODISED 2.3; heavily carinated scales, especially on head and neck, giving the snake a bristly appearance; Correspondence: R. Ernst, Theodor Boveri Institute Biocenter of the University, Department of Animal Ecology keels run in long curves towards a sharp tip; six and Tropical Biology (Zoology III), Am Hubland, D-97074 suprarostrals; eight to nine infralabials; three pairs of Wi.irzburg, Germany. sublinguals; elongate dorsal scales; 16 scale rows E-mail: [email protected] around mid-body. 56 R. ERNST ET AL. w I0° E 30° interorbitals; 14 scales between posterior supralabials; eye large, 3.1 mm in diameter; eye diameter 2.5. times the eye-border to lip distance; no interoculabial; 14 and 15 circumorbitals, fo ur in contact with supralabials; nine and 10 supralabials; mental twice as wide as long; eight and nine infralabials,first pair in contact posterior to mental; three pairs of sublinguals; three preventrals; two to three rows of keeled gular scales; dorsal scales heavily keeled, especially on head and anterior third of body; keels run curved to a sharp tip; lateral scales with­ out serration; no reticulate microdermatoglyphicpattern FIG. I. West and Central African distribution of A. of cell boundary lines; size of the scale keels decreases squamigera (circles) and type-locality ofA. hirsuta sp. nov. from head to tail; keels at mid-body shorter and with (triangle). Closed symbols represent localities of checked rather blunt tips; 16 scale rows around mid-body; 14 specimens, open symbols represent unchecked literature records; sources: Blanc & Fretey, 2000; Broadley, 1998; scale rows in the neck region; 14 scale rows anterior to Lawson & Ustach, 2000. vent; 160 ventrals, slightly keeled; 58 subcaudals. Coloration. Dorsal coloration in life is bronze; sev­ Description. Slender tree viper, 480 mm total length, eral scale tips and keels being dark-brown, forming an tail 95 mm; very short and sturdy head, IODISED 2.3; irregular pattern of broken crossbars; ventrally cream­ rostral three times as wide as deep, surmounted by six white to yellowish; iris yellow (Fig. 3). In preservative suprarostrals; viewed from the front the three median (3 % formaldehyde transferred to 70 % ethanol after two suprarostrals in the lower row increase in size from left months), colour changed to reddish-brown dorsally; to right; the upper row consists of three scales, the lat­ ventral scales turneduniform clear reddish brown, being eral ones larger than the median (Fig. 2c); five more intense in posterior third of body and tail, fading internasalsstrongly carinated; nasals undivided; a single anteriorly. scale row separates nasals from circumorbital scales; Etymology. The name refers to the hirsute appearance head scales heavily carinated and lanceolate; nine of the snake (!at. hirsutus =hairy, hirsute). TABLE 1. Head-measurements and indices of specimens examined. Data forAt heris squamigera are based on all material examined (n=23). Damaged specimens were excluded from the analysis. Measurements in mm. For abbreviations see the material and methods section. HL HW IOD SED HL/HW IODISED HWIIOD Atheris hirsuta sp. nov. 14.3 10.7 6.9 3.0 1.3 2.3 1.6 Atheris squamigera Mean 20.2 15.0 8.1 4.8 1.4 1.7 1.8 Mode 16.4 11.1 8.2 5.3 1.1 1.6 1.4 SD 4.1 3.3 1.4 1.0 0.1 0.1 0.2 Min 12.5 8.5 5.3 3.3 1.1 1.4 1.4 Max 28.9 22.1 11.8 7.2 1.7 1.9 2.2 TABLE 2. Head scalation of specimens examined. Data for Atheris squamigera are based on the entire material examined (n=44). Damaged specimens were excluded from the analysis. For abbreviations see the material and methods section. SRO INS IOS MTHS cos COS IOL ION SL SL IL IL PSL left right left right left right Atheris hirsuta sp. nov. 6.0 5.0 9.0 14.0 15.0 14.0 0.0 1.0 10.0 9.0 9.0 8.0 3.0 Atheris squamigera Mean 4 4 8 14 14 14 0 10 10 11 11 5 Mode 3 4 8 15 14 14 0 10 10 11 11 5 SD 1.5 0.6 0.7 1.1 1.4 1.3 0.3 0.4 1.0 0.9 1.0 1.2 0.6 Min 3 3 7 12 11 11 0 8 8 8 8 4 Max 8 6 10 17 17 17 2 12 12 12 13 7 A NEW ATHERIS SPECIES 57 TABLE 3. Body scalation and SYL in mm of specimens temperature are up to I 0°C. Mean annual temperature is examined. Data fo r Atheris squamigera are based on all about 25°C. Humidity fluctuates from 85% during the material examined (n=44). Damaged specimens were day to 90-100% during the night. This area is situated excluded from the analysis. • = + anal. For abbreviations see the material and methods section. within the equatorial climate zone, which is influenced by the southernpassat (Riezebos, Vooren & Guillaumet, MSR Ventralsa Sub- SVL 1994). Floristically it belongs to the Guinea-Congo Re­ caudals gion (Guillaumet, 1967). The holotype was found after Atheris heavy rain, on a dirt road between the small town ofTa"i hirs uta sp. nov. 16.0 160 58.0 480 and the SRET. This area is characterized by secondary rain forest. Atheris Behavioural remark. Compared to the sympatric A.